[PATCH] ci: avoid unnecessary builds

["Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

Whenever a branch is pushed to a repository which has GitHub Actions
enabled, a bunch of new workflow runs are started.

We sometimes see contributors push multiple branch updates in rapid
succession, which in conjunction with the impressive time swallowed by
even just a single CI build frequently leads to many queued-up runs.

This is particularly problematic in the case of Pull Requests where a
single contributor can easily (inadvertently) prevent timely builds for
other contributors.

To help with this situation, let's use the `concurrency` feature of
GitHub workflows, essentially canceling GitHub workflow runs that are
obsoleted by more recent runs:
https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    ci: avoid unnecessary builds
    
    Just something I noticed recently and only got around to implement
    today.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1404%2Fdscho%2Favoid-unnecessary-ci-builds-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1404/dscho/avoid-unnecessary-ci-builds-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1404

 .github/workflows/check-whitespace.yml | 5 +++++
 .github/workflows/l10n.yml             | 5 +++++
 .github/workflows/main.yml             | 5 +++++
 3 files changed, 15 insertions(+)

diff --git a/.github/workflows/check-whitespace.yml b/.github/workflows/check-whitespace.yml
index ad3466ad16e..8a4c4bfbb93 100644
--- a/.github/workflows/check-whitespace.yml
+++ b/.github/workflows/check-whitespace.yml
@@ -9,6 +9,11 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Avoid unnecessary builds
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check-whitespace:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/l10n.yml b/.github/workflows/l10n.yml
index 27f72f0ff34..77d9a416289 100644
--- a/.github/workflows/l10n.yml
+++ b/.github/workflows/l10n.yml
@@ -2,6 +2,11 @@ name: git-l10n
 
 on: [push, pull_request_target]
 
+# Avoid unnecessary builds
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   git-po-helper:
     if: >-
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 831f4df56c5..cf47f0ccfed 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -2,6 +2,11 @@ name: CI
 
 on: [push, pull_request]
 
+# Avoid unnecessary builds
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 env:
   DEVELOPER: 1
 

base-commit: e7e5c6f715b2de7bea0d39c7d2ba887335b40aa0
-- 
gitgitgadget